diff --git a/proxy.ts b/proxy.ts
index ae35447..6beee82 100644
--- a/proxy.ts
+++ b/proxy.ts
@@ -14,12 +14,18 @@ export async function proxy(request: NextRequest) {
 	);
 
 	if (!locale) {
-		const newLang = 
+		let newLang = 
 			request.headers
 				.get('accept-language')
 				?.split(',')[0]
-				?.split('-')[0]
-			?? 'en';
+				?.split('-')[0];
+
+		if (!newLang)
+			newLang = routing.defaultLocale;
+		else {
+			const langAvailable = (routing.locales as readonly string[]).includes(newLang);
+			if (!langAvailable) newLang = routing.defaultLocale;
+		}
 
 		const redirect = `/${newLang}`
 			+ request.nextUrl.pathname